Question

If x+y=20 and x2 + y2=40 what is x-Y

Answer 1

Step-by-step explanation:

We have,

(2x+y)

2

=(2x)

2

+y

2

+2×2x×y

⇒(2x+y)

2

=(4x

2

+y

2

)+4xy

⇒(2x+y)

2

=40+4×6⇒(2x+y)

2

=64

⇒2x+y=±

64

⇒2x+y=±8